1. Field of the Invention
The present invention relates to an image processing device suitable for application principally to video game devices, and more particularly to an image processing device whereby pictures such as explosions or smoke, whose form changes continuously, can be effectively represented.
2. Description of the Related Art
In conventional video game machines, there are a large number of "shooting games". In such shooting games, a peripheral device such as a gun unit is connected to the casing of the main unit of the game machine and the machine performs an evaluation as to whether a projectile displayed on the CRT has hit the target and displays an image of an explosion at the point where the projectile lands.
Typically the form of such an explosion may be anticipated to show a series of very considerable changes within a prescribed time. In existing video game machines there are therefore various conventional examples for effectively representing an explosion and for making this possible with a small amount of data.
A prior art technique of showing a player a powerful explosion three-dimensionally is known, in which, in order to reduce the amount of data, textures are mapped on to planar polygons and these are directed towards the viewpoint (camera). However, in this prior art example, it is very difficult to display an explosion three-dimensionally.
The prior art techniques are subject to the following problems. In the case of the prior art technique in which textures are mapped on to flat polygons, as described above, this results in the image of the explosion seen from the front always being presented even if the viewpoint is changed.